<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<div id="app">
  <!-- <input type="text" v-model="message">-->
  <!-- 实现方式：-->
  <input :value="message" type="text" v-on:input="message = $event.target.value">
  <h3>{{message}}</h3>
</div>
<script src="../js/vue.js"></script>
<script>
  const vm = new Vue({
    el: '#app',
    data: {
      message: '你好啊!!'
    },
  })
</script>

</body>
</html>